Decolorizing viscous lubricating oil



Jan. 12, 1937. c. F. TEARS DECOLORIZING VISCOUS LU BRICATING OIL Filed July 5, 1935 W k l k ns iz \Nn 1 Q 1 Qihia kmniixm .3 ER. E855 5 8M & Q wm xuumg ith in .isuesu I N E igs No 4 Lauri-BU m m I w. w I H m sag an Nu g. m M r .m

w M C Patented a... 12, "1931 nEcoLomzmG viscous LUBRIOATING on.

' Claude F. Tears, Mountain Lakes, N. J., assignor to The Petroleum Processes Corporation. Wichita, Kans., a corporation of Kansas Application July 5, 1933, Serial No. 679,073.

' 7 Claims.

11This invention relates to the decolorlzing of o a Important objects of the invention are to reduce the expense of operations, materials and equipment, to save solvent and oil losses that have heretofore been incidental to decolorizing processes, to increase the throughput per unit of clay and reduce the time required, to simplify operations and apparatus necessary and to produce in the end a more completely refined or better grade of oil product.

The attainment of these and other desirable objects is effected by thenovel features of process, apparatus and materials hereinafter disclosed and broadly claimed;

The drawing accompanying and forming part of the following specification illustrates by way of example one typical and. at the present time preferred form of apparatus for carrying out the invention.

The single view in the drawing is a flow sheet diagram illustrating the operation when embodied in a percolation filtration system.

Decolori'zing of oil, as well known, is usually effected. by use of an adsorbent earth, fuller's earth or clay as it is generally termed and a naphtha or gasoline diluent. .The percolation method involves the handling of great quantities of diluent and necessarily heavy losses in redistillation or recoveryof the same, extensive and expensive equipment for reactivation of the clay, expensive losses of oil and diluent in the burning of the clay andother relatively heavy expenses. The contact method requires the use of finer, more expensive clays, use of special equipment, losses of oil and diluent and exg penses in the recovery of the diluent. Also the fine clays used for contacting can not be reactivated economically in the present available 40 equipment. Both processes require a considerable volume of diluent in the system.

In the present invention, the useof 'a lesser quantity of diluent is made possible by the selection of one of especially low viscosity and great activity and by the operation of the proces in a closed system, practically free of losses. The diluent employed, preferably is a low viscosity hydrocarbon which is gaseous at ordinary temperatures andit is used in a closed system under pressure suflicient to maintain it in the liquid state. 4

Propane, because of its availability, low cost and the fact that it can be maintained liquid at a pressure of around 150 lbs. at normal temperatures has been used most satisfactorily, but

(CL19614'I),

butane and pentane, costing approximately the same, may be used. Methane and ethane may be used, but at present, cost more and require more expensive equipment to maintain the higher pressure necessary to hold them in the Others of the unsaturated series,

liquid state. such as ethylene, propylene and butylene may be employed, with modifications necessary to the handling of the same.

Theliquid propane or like diluent, because ,of its extremely low viscosity, penetrates the clay more completely and renders the clay more active or more effective in decolorizing and cleaning the oil. The pressure required to keep the diluent in the liquid form serves also whenopcrating according to percolation methods, as the pressure for operating the filter and recovery of diluent from the clay is made possible by simply releasing this pressure and removing the diluent as a recoverable gas. The propane or like dfluent also apparently has an activating effect on the clay, enabling the filter clay to be more or less reactivated by simply washing it in the filter with fresh propane at the end of a run.

The apparatus required is relatively simple, as will be apparent by reference to the accompanying illustration.

In this view, the oil to be decolorized is taken from a storage tank- I, and the propane or similar diluent, under pressure and. in the liquid state, is taken from a suitable holder 2, pumps 3 and 4, conveying the same under pressure through lines 5 and B, into a mixer I. To assure thorough intimate mixing, the mixture may then be passed by line 8, through a, suitable heater 9. From this heater, the mixture may be passed through line Ill, direct to the filter chamber ll, amend this is usually preferable,

4 the mixture may first be passed by line Ill-l2,

through cooler l3, and thence by line lL-IO to the filter, the cooling thus effected enabling operations at lower pressure. Valves IS, IS, II are located in the lines comiecting the heater and cooler and connecting these with the filter, so

I that such control may be exercised. Also, if desired, by proper control of these valves, the flow may be sent partly through the heater and partly through the cooler in series with the heater;

By proper control of the steam or other heating medium usedwith the heater and the water or other cooling medium used with the cooler, desired temperature and pressure conditions may be readily maintained.

The special diluent described makes it possible to use the cheapest grade of now obtainable, known proximately 100 mesh.

The pressure required to keep the propane liquid, ranging in the neighborhood of 150 lbs. at normal atmospheric temperatures is utilized and is a desirable pressure for operating the filter with a clay on the order of that mentioned. If desired or necessary theoperating temperatures may be higher and in such case the presdecolorizing clay as XXE. This is of apsure will of course be higher.

The throughput is shown as carried ofl from the filter through line It to being heated on the way, if desired, by a heater 20.

The stripper l9, may be of more or less usual construction, being shown with the decolorized oil passing off at the bottom at 2|, through cooler 22, to storage and the propane or like diluent passing off as a vapor at the topthrough line 23 and condenser 24, to a receiver 25. From the later, the return line 26, runs back to solvent storage 2. Receiver 25 is normally operated at sufllcient pressure to deliver the propane or like, in liquid form, back to the diluent storage tank.

After operating with the propane or like mixture to the desired color of product, the filter maybe washed with the propane or like diluent to remove the oil retained in the clay. This can be effected in the illustrationby closing the valve 21, in line 6, leading to the mixer and opening valves 28, in the propane. line 29, direct to the top of 'the filter, the oil retained by the clay coming. out with the propane at the bottom and being separated at the still l9, in the manner heretofore described. The liquid propane is so active as a cleaning agent as to remove practically all oil from the clay in the filter. It also A, apparently has some reactivating eflect on the clay. I

After washing, the propane may be recovered from the clay either simply by reducing pressure in the system and vaporizing the diluent to a compression and condensing system or with use of some heat to evaporate propane from the clay.

A heater for the latter purpose is indicated at 30. in the bottom of the filter. All, or practically all the propane can be removed and recovered through recovery lin'e 3|,

at the top of the filter and the compressor and condensation system as indicated at 32, 33, discharging through line 34, to the receiver 25. Thus, loss of diluent in the clay is practically entirely eliminated.

Because of the cheapness of the decolorizing medium which can be used in this system and .the thorough-"cleansing of the "same by the pro-1 pane or like diluent, it is economically feasible to discard the clay without burning, after it has become exhausted with repeated use in theoperations described.

It is however, commercially practical to ex-' tend the lite of the clay by including in the system a circuit for further cleaning and reactivating the dry clay which has been freed of pro-' pane or other diluent. Apparatus for the purpose is shown in the'illustration consisting of a holder 35, for a color removing solvent connected by line 36, with the top of the filter and a line 31, led 03 from the bottom oi! the filter to a still or stripper. From the bottom of this still, removed coloring matter is taken oil. at 89, through a cooler 40, and at the top the solvent is returned at 4|, to the holder 3!, through a cona still or stripper 19,.

,ation has the same advantages over diluent is remote.

denser 42. Valves are suitably placed to enable proper use of this color removing solvent, such ,as indicated at 43, 44, 45, and a suitable heater and in reactivating the clay.

After reactivating with trichlorethylene or some other suitable color removing solvent va number of times, the clay maybe discarded or, if the plant be already equipped with such apparatus, be reactivated in a suitable clay burner- The latter would probably be practiced in existing installations having clay burning equipment. using coarser clays of 30 to 60 or 60 to mesh and burning the clay after each propane filtration and after washing with trichlorethylene becomes no longer suificiently effective. The use of propane or the like, in the case of a plant equipped with a clay burner, has the advantages of increasing the yield of finished oil per ton of clay, reducing the diluent and oil losses in the clay and reducing the burning costs. In installations however, where no burningequipment is present, it is practical to use a cheap clay, such as the XXF clay mentioned by way of example, and to discard it without burning, after it has appreciably lost its activity in the processing described. In new systems, probably no burning equipment would be installed and ,hence such outlay would be entirely saved. x

The invention embraces other than percolation methods of filtration. Use of propane or like, with attendant advantages, may be employed in contact filtering, for example, as claimed in a separate divisional application, Serial No. 714,494, filed March 7, 1934, as follows:

Ai'ter mixture of the oil and line contact clay in an agitator, the slurry may be pumped to a pressure vessel by way of a pressure mixer through which the liquid propane or like diluent would be delivered. This pressure vessel would be equipped with suitable filter units, such as the bottom and delivering the same back into.

the middle portion of the chamber. This operform pt contact filters ,as thosevpointed out above in conjunction with the percolation method; Another and important advantage is that a cheaper decolorizing medium, such as the m clay mentioned, may be used for contacting instead or the more expensive 200 mesh untreated or much more expensivespecially treated clays commonly employed with contact filtration.

, The invention is suited to the decolorizing of any lubricating oil fractions of petroleum and -to the recovery of crank case oils and the like. The

there is only a relatively small volume or propane or like in the system at'all times. The system being closed and the pressure being normally of approximately lbs., the possibility of lost the filter bed, becaue of the lessened viscosity is The pressure drop through the usual I equipment required is comparatively simple, as

much lower than in previous systems employing naphtha as a diluent. v

Other miscible,normally gaseous diluents than those heretofore mentioned maybe employed, such for example as carbon dioxide, with pressure of the liquefied diluent utilized as the source of energy for pressure on the filtering medium. The blending for filtration purposes may be in the ratios from 1:1 up. With higher ratios of say 3 to 4 times the volume of diluent, the action is more rapid, resulting in quicker and more complete color removal with improvements in the character of final products. Apparently; in these greater viscosity reductions, isolation of certain pigment or colloidal compounds, which are normally in solution and inseparable from the oil is eflected without requiring excessively higher temperatures and these compounds are rapidly deposited on the clay. The avoidance of excessively high temperatures also avoids certain oxidation reactions with the clay as a catalyst or auto oxidant, avoiding condensing? of certain forms of coloring matter to be absorbed by the clay surfaces. With the higher temperatures as heretofore used, the clay finally became exhausted by being covered or filled with oxidized products. In the present process, without use ofsuch excessive heat, the pigment material is deposited in the clay without decomposition or oxidation, so that whereas heretofore the deposited matter could only be removed by burning,

in the present system the coloring materials are readily removed by solvent extraction with such asphalt and resinous solvents as trichlorethylene, carbon-tetrachloride, acetone, ether and like.

known solvents. I i The extreme dilution effected in this invention releasesthe semFdissolved or colloidal pigments and makes possible filtration through other filter mediums, such as filter paper and edge filters as described for contact filters. This may be accomplished with dilutions on the order of from 1:1 to 1,12. In further stages of dilution in the ranges of from 1:2 to 1:10 parts, that is, one part oil to ten parts solvent, different results are accomplished, enabling isolation and removal of the pigment materials by the clay, with still greater rapidity. These higher dilutions also enable use or other bleaching and filtering mediums, such as bone meal, carbon black, fuller's earth and specially treated decolorizing materials, with much greater efiiciency than in presentpractice. .By the solvent action of the diluent, the lower molecular weight compounds are apparently dissolved by the solvent and the heavier molecular weight materials are left in the pigment form for deposition on the clay. Eiltering by contact methods is therefore made the more complete. The recovery of the solvent efiected .simply by releasing the pressure andevaporating the normally gaseous material is particularly advantageous foruse in contacting with fine clays from which solvent removal has been particularly difiicult when using higher boiling point diluents such as naphtha. It will be apparent, that the'invention is adapted to the refining oi' vegetable and animal oils as well as mineral oils previously considered.

The much lower viscosity of the propane or similar liquefied normally gaseous diluent, such as those heretofore mentioned employed in this invention, as compared with naphtha and like diluents heretofore used, very materially speeds up the decolorizing and refining operation, enabling a plant comparable with present equipclay that much more active and effective.

only for a comparatively short period and this lesser time of contact, is also of advantage in operating on certain oils. The apparent reactivating died; of the diluent on" the decolorizing medium seemingly is a result of the very low viscosity of the diluent, which enables it to pene- 'trate deeper and to act on the clay, in a mannei not-accomplished with the naphtha and like diluents heretofore used. This greater penetration of the clayby the extremely low viscosity diluent in the decolorizing operation carries the oil deeper into the pores of the clay, making the The pressure and temperature may vary within wide limits. Thus in the case of propane and in accordance with temperature in the system, the pressure may varybetwe'en 150 and 1000 lbs.

The apparatus'illustrated, may be operated as a completely closed system, with the pressure required for holding the diluent in the liquid state.

generated in the' stripper l9. By c osely regulating the heater 4'! of this still and properly setting the pressure controller 48, of'the propane receiver 25, the desired pressure may be maintained in the system with a minimum loss from venting excess pressure to atmosphere at the pressure controller.

. After washing the clay with the color removing solute, solvent remaining in the: clay may be evaporated and recovered by use or heater 30 in the base of the filter, valve 49 in the vapor recovery line 3|, being open at such time, also the valve 50 in the by-pass 5|, about the compressor 32, s0 that flow is direct to condenser 33. The condensed solvent can then be directly returned to the holder 85, through line 34-42, after closing valve 53 and opening valve 54. This recovery system can thus be employed at diflerent times for recovery of diluent and color removing solvent, 'b'y-passing the compressor when not needed, as in the latter instance.- The decolorizing medium may be suitably supplied to the filter as by conveyor indicated at 55, the filter chamber being closed as indicated during processing operations. i

As the invention is of broad scope and capable of modification in various ways, the specification and claims are to be construed accordinglyand words and phrases employed herein have been used in a descriptive rather than in a limiting sense and are to be so considered, except possibly for limitations as may be required by state of the prior art.

What is claimed is:

1. The herein disclosed process of decolorizing viscous lubricating oil which comprises heating a mixture. of viscous lubricating oil and liquefied propane solvent under pressure .to eiTect comadsorbent decolorizing clay under pressure in ex- 3 cess of 150 pounds per square inch and distilling the vdecolorized solution under pressure to separatethe solvent from the decolorized oil. I

2. The process 'asiin claim 1 in which the solpropane solvent under pressure to effect comture through a bed of adsorbent decolorizing clay 5 plete solution and extreme dilution of the lubriunder sufllclent pressure to maintain the heated 'cating oil in the solvent, cooling the solution solution in the liquid state. under pressure to a temperature corresponding 6. The herein disclosed process of decolorizing to a solvent vapor pressure in excess 01 150 viscous lubricating oil which comprises heating pounds per square inch thereby reducing the a mixture of viscous lubricating oil and liquefied 10 solution to optimum decolorizing temperature. propane solvent under pressure sufilcient to passing the cooled solution through a bed of maintain said solvent in the liquid state to a adsorbent decolorizing clay under pressure in extemperature corresponding to a solvent vapor cess of 150 pounds per square inch and distilling pressure in excess of 150 pounds per square inch the decolorized solution under pressure to sepaand passing the heated mixture through a bed of 15 rate the solventirom the decolorlzed oil, and readsorbent decolorizing clay under suflicient presducingthe pressure on the bed of adsorbent desure to maintain the heated solution in the colorizlng clay to release the normally gaseous liquid state. v liquefied hydrocarbon solvent iromthe adsorbent 7. The process of claim 5, including the furdecolorizing clay inthe gaseous state, liquefying ther steps of periodically interrupting the 20 the solvent and recycling the same for the treatpassage of the oilsolution through the bed of ment of additional lutricatingoil. adsorbent. decolorizing clay and passing fresh 4. The process as in claim 3. in which the sol liquefied normally gaseous hydrocarbon solvent vent to oil ratio ranges between 1 to 1 and 10 under pressure 'sumcient to maintain the solvent to 1. in the liquid state through the bed of adsorbent 25 viscous lubricating oil which comprises heating a mixture of viscous lubricating oil and liquefied 5. The herein disclosedprocess of decoiorizing viscous lubricating oil which comprises heating a mixture of vviscous lubricating oil and liquefied normally gaseous hydrocarbon solvent to a temperature correspondingto a solvent vapor pressure in excessof 150 pounds per square inch under pressure sumcient to maintain said solvent in the liquid state and passing the heated mixdecolorizing clay during such periods of interrupted flow or oil solution.

' CLAUDE F. TEARS.

DISCLAIMER v 2;067,802.0laude F. Tears, Mountain Lakes, N. J. Dnoonomzms -VISCOU8 Patent dated January 12, 1937.

Disclaimer filed October 28, 1939, by the assignee, The Petroleum Processes Corporation. Hereby disclaims claims 5, 6, and 7 in any interpretation that would include heating a mixture of viscous lubricating oil and liquefied normally gaseous hydrocarbon solvent, or propane, or mixtures. of propane and butane sometimes defined or termed propane or commercial propane solvents, to temperaturesof not more than F., or not under pressure sufliclent to maintain the solvent in such mixtures in a liquid state, or not passing the heated mixture thro h the bed of adsorbent decolorizing clay under suflicient pressure to mamtam t e solvent in the heatedsolution in the liquid state while in contact with the adsorbent decolorizing clay. l

[Ofiim'al Gazette November 21, 1939.]

propane solvent under pressure to effect comture through a bed of adsorbent decolorizing clay 5 plete solution and extreme dilution of the lubriunder sufllclent pressure to maintain the heated 'cating oil in the solvent, cooling the solution solution in the liquid state. under pressure to a temperature corresponding 6. The herein disclosed process of decolorizing to a solvent vapor pressure in excess 01 150 viscous lubricating oil which comprises heating pounds per square inch thereby reducing the a mixture of viscous lubricating oil and liquefied 10 solution to optimum decolorizing temperature. propane solvent under pressure sufilcient to passing the cooled solution through a bed of maintain said solvent in the liquid state to a adsorbent decolorizing clay under pressure in extemperature corresponding to a solvent vapor cess of 150 pounds per square inch and distilling pressure in excess of 150 pounds per square inch the decolorized solution under pressure to sepaand passing the heated mixture through a bed of 15 rate the solventirom the decolorlzed oil, and readsorbent decolorizing clay under suflicient presducingthe pressure on the bed of adsorbent desure to maintain the heated solution in the colorizlng clay to release the normally gaseous liquid state. v liquefied hydrocarbon solvent iromthe adsorbent 7. The process of claim 5, including the furdecolorizing clay inthe gaseous state, liquefying ther steps of periodically interrupting the 20 the solvent and recycling the same for the treatpassage of the oilsolution through the bed of ment of additional lutricatingoil. adsorbent. decolorizing clay and passing fresh 4. The process as in claim 3. in which the sol liquefied normally gaseous hydrocarbon solvent vent to oil ratio ranges between 1 to 1 and 10 under pressure 'sumcient to maintain the solvent to 1. in the liquid state through the bed of adsorbent 25 viscous lubricating oil which comprises heating a mixture of viscous lubricating oil and liquefied 5. The herein disclosedprocess of decoiorizing viscous lubricating oil which comprises heating a mixture of vviscous lubricating oil and liquefied normally gaseous hydrocarbon solvent to a temperature correspondingto a solvent vapor pressure in excessof 150 pounds per square inch under pressure sumcient to maintain said solvent in the liquid state and passing the heated mixdecolorizing clay during such periods of interrupted flow or oil solution.

' CLAUDE F. TEARS.

DISCLAIMER v 2;067,802.0laude F. Tears, Mountain Lakes, N. J. Dnoonomzms -VISCOU8 Patent dated January 12, 1937.

Disclaimer filed October 28, 1939, by the assignee, The Petroleum Processes Corporation. Hereby disclaims claims 5, 6, and 7 in any interpretation that would include heating a mixture of viscous lubricating oil and liquefied normally gaseous hydrocarbon solvent, or propane, or mixtures. of propane and butane sometimes defined or termed propane or commercial propane solvents, to temperaturesof not more than F., or not under pressure sufliclent to maintain the solvent in such mixtures in a liquid state, or not passing the heated mixture thro h the bed of adsorbent decolorizing clay under suflicient pressure to mamtam t e solvent in the heatedsolution in the liquid state while in contact with the adsorbent decolorizing clay. l

[Ofiim'al Gazette November 21, 1939.] 

